JP2017197845A - Process for forming silica coating on glass substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an improved chemical vapor deposition process for depositing a silica layer on a glass substrate.SOLUTION: In a chemical vapor deposition process, a glass substrate 8 is prepared, and a gaseous precursor substance mixture containing a silane compound, oxygen, steam of 10% or higher, and a radical scavenger is formed, and the precursor substance mixture is circulated in parallel to the substrate in a direction of the glass substrate 8, and the mixture is reacted on the glass substrate 8, to thereby form a silica coating on the substrate at a vapor deposition rate of about 150 nm/min or higher.SELECTED DRAWING: Figure 1

Description

The present invention generally relates to chemical vapor deposition (CVD) processes for forming coated glass articles and the coated glass articles formed thereby. In particular, the present invention relates to a CVD process for forming a silica coating on a glass substrate, and a glass article having a silica coating.

Silica coatings deposited on glass substrates are known. However, known processes for the formation of silica coatings are limited in terms of the efficiency of the deposition process and / or in terms of powder formation of the reaction components (pre-reaction). Accordingly, it is an object to develop an improved process for forming a silica coating on a glass substrate.

In a first aspect, the present invention provides a glass substrate, forms a gaseous precursor mixture comprising a silane compound, oxygen, water vapor, and a radical scavenger, and parallel to the substrate in the direction of the glass substrate. Flowing a precursor mixture and reacting the mixture on a glass substrate to form a silica coating on the substrate.

Preferably, the gaseous precursor mixture contains 10% or more water vapor. Preferably, the gaseous precursor mixture contains 40% or more water vapor. Preferably, the silica coating is
It is formed at a deposition rate of about 150 nm * m / min or more. Preferably, when the silica coating is formed on the substrate, the surface of the substrate is substantially at atmospheric pressure.

Preferably, the chemical vapor deposition process further comprises depositing a tin oxide coating on the surface of the glass substrate, preferably the silica coating is deposited on the tin oxide coating. Preferably, the tin oxide coating is deposited with a thickness of 5 nm to 100 nm. Preferably, the tin oxide coating is deposited using a halogen-containing tin precursor compound. Preferably, when the tin oxide, and preferably the silica coating, is deposited on the glass substrate, the surface of the substrate is substantially at atmospheric pressure.

Preferably, the gaseous precursor mixture is formed before being introduced into the coating apparatus. Preferably, the glass substrate is about 1 when the silica coating is deposited on the substrate.
100 ° F (600 ° C) to 1400 ° F (750 ° C).

Preferably, the glass substrate is moving when the silica coating is deposited. Preferably, the glass substrate is 125 in / min (3.175 m / min) to 600 in / mi.
It is moving at a speed of n (15.24 m / min).

Preferably, the gaseous precursor mixture contains 50% to 98% water vapor. Preferably,
The gaseous precursor mixture contains oxygen and silane compounds in a ratio exceeding 4: 1.

In a further aspect, the present invention provides a chemical vapor deposition process for depositing a silica coating, the process comprising providing a function of moving a glass substrate having a surface on which the silica coating is deposited, tin oxidation on the surface of the glass substrate. Depositing a metal coating, mixing a gaseous silane compound, oxygen, radical scavenger and water vapor to form a gaseous precursor mixture, and moving the gaseous precursor mixture toward the tin oxide coating surface of the glass substrate Flowing parallel to the surface; reacting the mixture at or near the coated substrate surface to form a silica coating on the surface; and cooling the coated glass substrate to room temperature.

Preferably, the surface of the glass substrate is substantially at atmospheric pressure when the tin oxide and, preferably, the silica coating is deposited on the surface.

Preferably, the tin oxide coating is 5 nm to 100 nm thick, preferably
It is directly deposited on the surface of the glass substrate. Preferably, the tin oxide coating is deposited using a halogen-containing tin precursor compound.

Preferably, the glass substrate is about 110 when the silica coating is deposited on the substrate.
It is 0 ° F (600 ° C) to 1400 ° F (750 ° C). Preferably, the glass substrate is 1
It moves at a speed of 25 in / min to 600 in / min.

Preferably, the tin oxide and silica coating forms two separate coating layers on the glass substrate. Preferably, the gaseous precursor mixture contains more than 10% water vapor.

All features described herein can be combined in any combination with any one of the above aspects.

  A chemical vapor deposition process is provided for depositing a silica coating.

In certain embodiments, the process includes providing a glass substrate. The process also includes forming a gaseous precursor mixture that includes a silane compound, oxygen, water vapor, and a radical scavenger. The process includes flowing the precursor mixture in the direction of the glass substrate, parallel along the substrate, and reacting the mixture on the glass substrate to form a silica coating on the substrate.

In another embodiment, the process includes provision of a function to move the glass substrate. The glass substrate has a surface on which a silica coating is deposited. The process also includes depositing a tin oxide coating on the surface of the glass substrate. The gaseous silane compound, oxygen, radical scavenger and water vapor are mixed to form a gaseous precursor mixture. This process also allows the gaseous precursor mixture to flow in the direction of the tin oxide coated surface of the glass substrate in parallel with the surface to react the mixture at or near the coated substrate surface to form a silica coating on the surface. And cooling the coated glass substrate to room temperature.

Those skilled in the art will appreciate the above and other advantages of the present invention in view of the accompanying figures.
It will be readily apparent from the following detailed description.

It is a schematic diagram of a float glass manufacturing process.

DETAILED DESCRIPTION OF THE INVENTION It will be understood that the invention may assume various alternative orientations and order of steps, unless explicitly stated to the contrary. It will also be understood that the specific articles and processes shown in the accompanying drawings and described in the following specification are merely exemplary embodiments of the inventive concepts. Therefore, unless explicitly stated otherwise,
Certain dimensions, orientations, or other physical characteristics associated with the disclosed embodiments should not be considered limiting.

In certain embodiments, a coated glass article for use as a superstrate in the manufacture of solar cells is described. However, it will also be appreciated by those skilled in the art that the coated glass article can also be used as a substrate in solar cell manufacturing. Furthermore, the coated glass article described herein is not limited to application to solar cells. For example, coated glass articles can be used in architectural glazing, electronics, and / or applied to automobiles and aerospace.

In certain embodiments, a CVD process for deposition of a silica coating is provided. A non-limiting feature of this process embodiment is the ability to deposit silica coatings at commercially practical deposition rates. For example, in certain embodiments, the silica coating is about 15
0 nm * m / min. Vapor deposition can be performed at the above deposition rate.

A silica coating as defined herein is a coating that contains primarily silicon and oxygen, and in some cases, trace amounts of contaminants such as carbon. In a preferred embodiment, the silica coating is stoichiometrically silicon dioxide (SiO ₂ ). However, a slightly oxygen deficient silica coating may be produced and can be used. Thus, the silica coating may be suitable close to stoichiometry.

In certain embodiments, the CVD process includes providing a glass substrate. This process can also be performed simultaneously with the production of the glass substrate. In this embodiment, the glass substrate can be formed utilizing a well-known float glass manufacturing process. An example of a float glass manufacturing process is shown in FIG. In this embodiment, the glass substrate is a glass ribbon 8.
It may be. However, it should be understood that the process can be utilized separately from the float glass manufacturing process or well after subsequent processing such as substrate formation and / or cutting.

Preferably, the glass substrate is moving at the time of formation of the silica coating. Therefore,
In certain embodiments, the process is a dynamic deposition process. Further, in certain embodiments, the temperature of the glass substrate is about 1100 when the silica coating is deposited on the substrate.
It is ° F (600 ° C) to 1400 ° F (750 ° C).

In some embodiments, the glass substrate is soda-lime-silica glass. In this embodiment, the glass substrate may be substantially transparent. However, since a translucent glass substrate can also be used for carrying out the process, the process is not limited to the use of a transparent glass substrate. Furthermore, the transparency of the substrate may vary depending on the composition and thickness of the glass substrate. Therefore,
For example, the process is not limited to the composition or thickness of the glass substrate because the process can be performed using transparent, blue, green, gray, and bronze glass substrates. Furthermore, this process can be carried out using glass substrates having various absorption characteristics. For example, it may be preferable to utilize a glass substrate with a low iron content.

The process also includes forming a gaseous precursor mixture. The precursor mixture may include precursors suitable for forming a silica coating at substantially atmospheric pressure.
Such materials may be liquid or solid at some point, but are volatile and can evaporate to form a gaseous precursor for use as a precursor mixture.

The gaseous precursor mixture includes a silane compound. In some embodiments, the silane compound is
It may be monosilane (SiH ₄ ). However, the process is not limited to monosilane, since other silane compounds are also suitable for use in carrying out the process.

The gaseous precursor mixture also includes oxygen. In certain embodiments, oxygen (O ₂ ) may be provided as part of a gaseous composition such as air. In another embodiment, the oxygen is provided in a substantially purified form. In either embodiment, the oxygen is in the form of molecular oxygen.

Typically, CVD deposition of a gaseous precursor stream containing only a silane compound produces an amorphous silicon coating on the substrate. However, silane compounds may be pyrophoric, and when single oxygen is added to the pyrophoric silane compound, silica is produced, but is produced at a very high rate, causing an explosion reaction. Known methods to prevent such explosive reactions result in coatings that are very slow and result in commercially impractical rates of deposition, which typically results in unacceptable thin layers. Also, the known methods limit the amount of silane and oxygen that can be included in the reaction mixture because, if the concentration is too high, gas phase reactions of the components occur and no thin film is formed. Thus, the gaseous precursor mixture includes a radical scavenger.

The presence of the radical scavenger allows the silane compound to be premixed with oxygen without ignition and premature reaction at the process operating temperature. The radical scavenger further provides control of the kinetics of the CVD reaction on the glass substrate and allows optimization. In certain embodiments, the radical scavenger is a hydrocarbon gas. Preferably, the hydrocarbon gas is ethylene (C ₂ H ₄ ) or propylene (C ₃ H ₆ ). US Pat. No. 5,798,142 describes silane, oxygen,
It teaches the formation of a silica coating by combining a radical scavenger and a carrier gas to form a precursor mixture (this patent is incorporated herein by reference in its entirety).

The gaseous precursor mixture includes water vapor. The process is not limited by the concentration of water vapor in the precursor mixture, but the addition of a high concentration of water vapor achieves a higher silica coating deposition rate than, for example, molecular oxygen alone as the oxidant. It was discovered. Thus, in certain embodiments, the gaseous precursor mixture comprises about 10% or more water vapor. In another embodiment, the gaseous precursor mixture comprises greater than 10% water vapor. Furthermore, it has been discovered that in certain embodiments involving higher concentrations of water vapor, for example, greater than about 20%, in the precursor mixture, a very large deposition rate increase is achieved. In still further embodiments, the precursor mixture includes a higher proportion of water vapor. For example, the precursor mixture may contain more than 40% water vapor. Preferably, in this embodiment, the precursor mixture contains 50% to 98% water vapor, and even more preferably 50% to 9%.
Contains 0% water vapor. Benefits obtained by including water vapor in the precursor gas mixture include:
Dynamic deposition rates on the order of 12 nm / sec or about 150 nm * m / min or higher are included.

In certain embodiments, the gaseous precursor mixture includes monosilane, oxygen, water vapor, and ethylene. In this embodiment, the gaseous precursor mixture comprises about 0.19% or more monosilane, about 0.4 to 0.8% or more oxygen, about 10% or more water vapor, and about 1.1% or more ethylene. Can be included. Even more preferably, in this embodiment, the precursor mixture comprises about 0.21% or more monosilane, 0.8% or more oxygen, about 40% or more water vapor, and about 1.2% or more ethylene. be able to. In a further embodiment, the precursor mixture comprises about 0.19% to about 1.2% monosilane, 0.8% to about 4.8% oxygen, about 40% or more water vapor, and about 1.1%. Up to about 7.2% ethylene.

Thus, in certain present process embodiments, the ratio of oxygen to silane compound in the precursor mixture may be about 4: 1 or greater. However, in other present process embodiments, it may be preferred that the precursor mixture comprises a high concentration of water vapor and a higher concentration of oxygen. High concentrations of water vapor and higher concentrations of oxygen in the precursor mixture can result in an increased deposition rate of the silica coating and can reduce the amount of reaction by-products generated during the deposition of the silica coating. Thus, in some embodiments, the precursor mixture can include an oxygen to silane compound ratio of about 7: 1 or greater. In a further embodiment, the precursor mixture can include oxygen in a ratio of oxygen to silane compound of about 10: 1 or greater. In yet a further embodiment, the precursor mixture can include an oxygen to silane compound ratio of about 20: 1 or greater oxygen. It should also be understood that water vapor and ethylene are also included in the precursor mixture of these embodiments in the proportions described above.

Preferably, in certain embodiments as shown in FIG. 1, the precursor mixture is introduced into the coating apparatus 9 prior to silica coating formation. In this embodiment, the precursor mixture may be formed before the precursor is introduced into the coating apparatus 9. In this embodiment, the precursors can be mixed in a gas mixing chamber or the like to form a gaseous precursor mixture. For example, the precursor can be mixed in a supply path connected to the inlet of the coating apparatus 9. In other embodiments, the precursor mixture can be formed in the coating apparatus 9. A description of coating equipment suitable for carrying out the process can be found in US patent application Ser. No. 13 / 426,697 and US Pat. No. 4,922,853. The entire disclosure of these patents is incorporated by reference.

The process also involves flowing the precursor mixture in the direction of the glass substrate and parallel to the substrate,
And reacting the mixture on a glass substrate to form a silica coating on the substrate. The precursor mixture is preferably laminar, in the direction of the glass substrate, parallel to the substrate,
Be guided. Also, the precursor mixture preferably has a glass substrate at a predetermined speed, for example,
While moving at a speed in excess of 125 in / min (3.175 m / min), it reacts at or near the glass substrate surface to form a silica coating. In another embodiment,
The glass substrate is moving at a speed of 125 in / min to 600 in / min (15.24 m / min).

As discussed above, the process can be performed simultaneously with the manufacture of the glass substrate in a well-known float glass manufacturing process. The float glass manufacturing process is typically performed utilizing the float glass facility 10 described herein and shown in FIG. However, it should be understood that FIG. 1 is illustrative of such equipment and is not intended to limit the present invention.

More specifically, the float glass facility 10 includes a canal unit 20 that sends a molten glass 19 from a melting furnace to a float bath unit 11 on which a glass substrate is formed.
In this embodiment, the glass substrate is called a glass ribbon 8. Glass ribbon 8 is a preferred substrate on which a silica coating is deposited. However, it should be understood that the glass substrate is not limited to being a glass ribbon 8.

The glass ribbon 8 is connected to the adjacent annealing furnace 1 from the bus 11.
2 and the cooling unit 13. The float bath portion 11 includes a furnace bottom portion 14 in which a bath of molten tin 15 is accommodated, a roof 16, an opposite side wall (not shown), and an end wall 17. The roof 16, side walls and end walls 17 together define a surrounding wall in which a non-oxidizing atmosphere is maintained to prevent oxidation of the molten tin 15.

During operation, the molten glass 19 is controlled in a controlled amount along the canal 20 with the adjusting twill (t
(weel) 21 downward and flows onto the surface of the tin bath 15. On the surface of the molten tin, the molten glass 19 spreads laterally by the action of gravity and surface tension as well as a specific mechanical action, and further proceeds through the tin bath 15 to form the glass ribbon 8. The glass ribbon 8 is taken out from the bus unit 11 over the lift-out roll 22 and then conveyed through the slow cooling furnace 12 and the cooling unit 13 on the aligned rolls. The silica coating is preferably deposited in the float bath section 11, but can also be deposited in the gap 28 between the float bath 11 and the slow cooling furnace 12, or in the slow cooling furnace 12 later in the glass production line. It is.

The silica coating is preferably formed at substantially atmospheric pressure. Accordingly, the pressure in the float bath portion 11, the slow cooling furnace 12, and / or the gap 28 between the float bath 11 and the slow cooling furnace 12 may be substantially atmospheric pressure. However, the process is not limited to atmospheric CVD processes. Thus, the silica coating may be formed under low pressure conditions.

In the float bath 11, an appropriate non-oxidizing atmosphere, usually nitrogen or a mixture of nitrogen and hydrogen containing nitrogen as a main component, is maintained to prevent oxidation of the molten tin 15 constituting the float bath. Ambient gas is introduced through a conduit 23 that is operably connected to the distribution manifold 24. The non-oxidizing gas is introduced at a rate sufficient to compensate for normal losses and to maintain a slight positive pressure on the order of about 0.001 to about 0.01 atmosphere from the ambient atmospheric pressure, thereby reducing the external atmosphere. Prevent intrusion. For the purposes of the present invention, the pressure range can be considered as standard pressure.

Heat for maintaining the desired temperature setting of the float bath 11 is supplied by a radiant heater 25 in the enclosure. In a typical example, the atmosphere in the furnace 12 is air, and the cooling unit 1
Since 3 is not surrounded, the glass ribbon 8 is thus open to the atmosphere. After forming the coating layer, the coated glass substrate is subsequently cooled to room temperature. In order to cool the coated glass substrate, the outside air can be directed toward the glass ribbon 8 by the fan 26 in the cooling unit 13 or the like. Also, a heater (not shown) is provided in the slow cooling furnace 12,
The temperature of the glass ribbon 8 can be gradually lowered according to a predetermined setting while the whole is conveyed.

In an embodiment, the coating apparatus 9 is provided with the function of directing the gaseous precursor gas mixture in the direction of the glass substrate and parallel to the substrate. The coating apparatus 9 may include one or more gas distributor beams. It should be understood that multiple coating devices, and therefore additional gas distribution beams, can supply the precursor to form an additional coating layer on the glass substrate. In a specific embodiment, the coating apparatus 9 is preferably a float bath unit 11, a slow cooling furnace 12,
And / or supplied into the gap 28 between the float bath 11 and the slow cooling furnace 12 and spreads laterally over the entire glass substrate. Depending on the required silica coating thickness, the silica coating formed by the present process can be deposited by successively forming multiple silica coating layers. However, the improvements provided by the present process may be sufficient to form a silica coating with only a single layer coating apparatus.

This process results in the deposition of a high quality silica coating on a glass substrate. In certain embodiments, the silica coating is a pyrolytic coating. In another embodiment, the silica coating is formed directly on the glass substrate. However, the maximum coating growth rate of the process is achieved when the silica coating is formed directly on the previously deposited tin oxide coating (SnO ₂ ). Thus, in certain embodiments, the silica coating is formed directly on the tin oxide coating. In this embodiment, the tin oxide coating has been previously deposited on the surface of the glass substrate. Thus, the tin oxide coating on which the silica coating is deposited can be deposited directly on the glass substrate.

The tin oxide coating may be formed just before the silica coating. In certain embodiments, the tin oxide coating can be formed simultaneously with the float glass manufacturing process.
However, it should be understood that the tin oxide coating can be formed using other manufacturing processes. If the tin oxide coating is formed simultaneously with the float glass manufacturing process, the tin oxide coating can be deposited by chemical vapor deposition using the coating apparatus 9A and / or at substantially atmospheric pressure. In these embodiments, the deposition of the tin oxide coating is preferably performed in the float bath section 11. However, it will be appreciated that the tin oxide coating can be formed using a different deposition process under low pressure conditions and without using a coating apparatus.

In certain embodiments, the tin oxide coating is a pyrolytic coating. Tin oxide coating, halogen-containing tin precursor compounds, preferably, Cl ^- can be formed with a containing precursor compound. Preferred Cl used for tin oxide coatings formed ^- containing precursor compound, dimethyl tin dichloride (DMT) and tin tetrachloride (SnCl ₄
).

In certain embodiments, the tin oxide coating was deposited directly on the glass substrate with a thickness of 5-100 nm. Preferably, in this embodiment, the tin oxide coating is
Vapor deposited with a thickness of about 25 nm. Thus, in embodiments where the tin oxide coating is deposited prior to silica layer formation, at least two separate coating layers are deposited on the glass substrate.

As described, in certain embodiments, the coated glass article can be composed of a glass / silica or glass / tin oxide / silica arrangement. However, the process may be utilized in combination with one or more additional coating layers to achieve the desired coating stack. The additional coating layer may be formed immediately after the formation of the silica coating, simultaneously with the float glass manufacturing process and / or as part of another manufacturing process.
These additional coating layers can also be formed by pyrolysis or by another coating deposition process.

As an example, an additional coating layer of thin film photovoltaic material, or other semiconductor material, can be formed on the silica coating layer, thereby obtaining the desired coating stack. A photovoltaic material, or semiconductor material, can be formed on the coated glass article during the manufacture of the solar cell. Because the silica coating of this process is of high quality, the coated glass article is formed by a different process, but has a higher visible light transmission than previously known coated glass articles having a silica coating that is the same coating stack. May indicate. Thus, the use of the present coated glass article in solar cell manufacture can result in higher solar cell efficiency and / or greater output.

In addition, coating layers of other materials can be deposited on the silica coating layer, resulting in a coating stack, thus providing a coated glass article with high conductivity, low emissivity and / or anti-reflective properties. It is done. In some embodiments, these additional materials may be transparent conductive metal oxides (TCO). Examples of such TCO materials are fluorine doped tin oxide (SnO ₂ : F) and aluminum doped zinc oxide (ZnO: Al).
It is. However, in certain embodiments, the transparent metal oxide material need not be electrically conductive in order to achieve the desired coating stack. In these embodiments, transparent metal oxide materials such as tin oxide, additional layers of silica, iron oxide (Fe ₂ O ₃ ), and titanium oxide (TiO ₂ ) may be formed on the silica coating. Good.

In Examples Tables 1, 2, and 3, columns showing the characteristics of the silica coating and the characteristics of the silica deposition process related to it are shown with SiO ₂ . Examples within the scope of the present invention are shown in Tables 1, 2 and 3 as Ex1-Ex21. However, Ex1-Ex21 are for illustrative purposes only and should not be construed as limitations on the present invention. Comparative examples not considered part of the present invention are shown as C1 and C2.

The following experimental conditions are applicable to C1, C2 and Ex1-Ex21.
C1, coated glass article of C2 and Ex1~Ex21 a glass / SnO ₂ / silica /
It is the arrangement of SnO ₂ : F. The coated glass articles listed in Tables 1, 2 and 3 were deposited on a moving glass substrate simultaneously with the float glass manufacturing process. For C1, C2 and Ex1-Ex21 prior to silica coating formation, a thermally decomposable SnO ₂ coating was deposited on a glass substrate with a thickness of about 25 nm. A SnO ₂ coating was formed using DMT. After formation of the silica coating, a thermally decomposable SnO ₂ : F coating was deposited on the silica coating at a thickness of about 340 nm.

The total gas flow of the gaseous precursor mixture of all components is 166 per meter of gas distribution beam in a direction perpendicular to the glass substrate movement direction per minute for C1, C2 and Ex1-Ex15.
For liters (166 l / min / m) and Ex16 to Ex21, 224 l /
min / m. The amounts of individual gaseous precursors are listed in Tables 1, 2 and 3. The line speed, ie the speed at which the glass substrate moves under the coating apparatus into which the precursor gas is fed, was 5.94 m / min and 10.5 m / min, respectively.

The deposition rate for the purpose of this application is expressed in two ways:
(1) The dynamic deposition rate (DDR) is equal to a value obtained by multiplying the thickness (nm) of the silica coating by the line speed (m / min), and is expressed as nm * m / min. DDR is useful for comparing coating deposition rates at different line speeds.

(2) Concentration-controlled dynamic deposition rate (CA-DDR) is equal to DDR divided by the concentration of silane in the precursor mixture (% SiH ₄ ). CA-DDR is (nm * m / min) /% S
represented by iH _4, in the case of the silica coating having a different precursor concentrations at different line speeds, useful for comparing the deposition rate.

The silica coating thickness reported in Tables 1, 2 and 3 was calculated using reflection. Also,
For the reported example, the% improvement is a comparison of the CA-DDR of the known process (C1, C2) with the CA-DDR of the process described herein. On the other hand,% Tvis is the total visible light transmittance of the coated glass article produced by the comparative silica deposition process C2 and the process described herein, expressed as a percentage.

As shown in Ex1-Ex21, this process provides an improved process over the comparative silica deposition processes C1 and C2. For example, silica deposition process C of the comparative example
The silica film thickness of 2 is 24.8 at a concentration of 0.57 SiH ₄ mol% in the gaseous precursor mixture.
nm. However, in ex10 and ex11, the silica film thickness is 25.
7 and 25.5. This is the result obtained even though SiH ₄ mol% in the gaseous precursor mixture at ex10 and ex11 was only 0.36 and 0.34, respectively. Also, SiH ₄ mol in the gaseous precursor mixture as shown by the silica deposition rate of Ex1 and Ex3 to Ex7 and the silica deposition process C1 of the comparative example.
If the% is the same, the silica deposition rate of the process is greater than the rate of the comparative deposition process.

In addition, Ex1 and Ex3-Ex7 show the effect of increasing water vapor in the precursor mixture on the silica deposition rate. As shown in the figure, the silica deposition rate increases as the percentage of water vapor in the precursor mixture increases. Table 1 As can be seen from Ex1 and Ex3～Ex9, when the ratio of SiH ₄ relative to _{O 2} and _C 2 _{H 4,} for example, in a ratio of 1-4-6, which is held substantially the same, the gaseous precursors The additional water vapor in the mixture usually leads to an increase in silica coating thickness and an improved silica deposition rate. For example, Ex12 to E in Table 2
At x15, the silica coating thickness and the silica deposition rate are the same as the deposition process C of the comparative example.
2 shows a large increase exceeding 16%. Also, as can be seen from the silica deposition rate comparison between Ex1 and Ex3 to Ex9, an increase in water content usually leads to a substantial increase in silica coating thickness and an improvement of more than 8.5% in silica deposition rate. Furthermore, an increase in water vapor mol% in the gaseous precursor mixture usually leads to an increase in silica coating thickness and an improved silica deposition rate. For example, in Ex12 to Ex15 in Table 2, the silica coating thickness and silica deposition rate show a large increase of over 16% over the comparative deposition process C2.

Thus, as can be seen, the process provides a more efficient process that produces a higher silica deposition rate than the comparative deposition process.

Table 3 shows the advantages of using high concentrations of water vapor and higher concentrations of oxygen in the process. Ex. 16, the silica coating is 230 nm * m / m when the water vapor concentration in the precursor mixture is 58.4 and the ratio of oxygen to silane compound in the precursor mixture is about 4: 1.
Deposited in DDR. However, as shown in Ex17-Ex21, DDR increases as the ratio of oxygen to silane compound in the precursor mixture increases. For example, Ex
In 17, the silica coating was deposited with a DDR of 251 nm * m / min. In this example, the percentage of water vapor in the precursor mixture was maintained at 58.4, but the ratio of oxygen to silane compound in the precursor mixture was about 7: 1. In Ex18, the water vapor concentration is 58.
While maintained at 4%, the silica coating was deposited with a DDR of 272 nm * m / min. However, the ratio of oxygen to silane compound in the precursor mixture was increased to about 10: 1. At Ex19, a further increase in silica coating was observed, but in this case,
A silica coating was deposited with a DDR of 277 nm * m / min when the ratio of oxygen to silane compound in the precursor mixture was about 15: 1. At Ex20, the oxygen to silane compound ratio in the precursor mixture is about 20: 1 and the silica coating is 251 nm * m
Vapor deposition was performed at DDR / min. Ex21 shows that an improvement in silica coating DDR can be achieved when the ratio of oxygen to silane compound in the precursor mixture is 20: 1 or higher.

Furthermore, the coated glass article formed by this process has a higher visible light transmittance than the coated glass article obtained by the vapor deposition process of the comparative example. For example, as shown in Table 2, the visible light transmittance of the coated glass articles ex11 to ex15 is higher than the visible light transmittance by the vapor deposition process C2 of the comparative example.

The foregoing description is considered as illustrative only of the principles of the invention. Further, those skilled in the art will readily recognize many modifications and changes and therefore are not intended to limit the invention to the exact constructions and processes shown and described herein. Accordingly, all suitable modifications and equivalents may be considered as falling within the scope of the invention as defined by the following claims.

The reader's interest is directed to all papers and documents filed simultaneously with or in advance with this application and published with this specification, and all such papers and documents. The contents of are incorporated herein by reference.

All features disclosed in this specification (including all accompanying claims, abstracts and figures), and / or all steps of any method or process so disclosed, are at least in part Such combinations and / or steps may be combined in any combination except where the steps are mutually exclusive.

Unless expressly stated otherwise, each disclosed feature (including all accompanying claims, abstracts and figures) in this specification is intended to serve the same, equivalent or similar purpose. May be substituted with an alternative feature that fulfills Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The present invention is not limited to the detailed description of the previous embodiment. The present invention is directed to any novel feature, or any novel combination of features disclosed herein (including all accompanying claims, summaries and figures), or any method or method thus disclosed. Includes any new step or any new combination of process steps.

Claims (20)

A chemical vapor deposition process for depositing a silica coating,
Preparing a glass substrate,
Forming a gaseous precursor mixture comprising a silane compound, oxygen, water vapor, and a radical scavenger; and flowing the precursor mixture in the direction of the glass substrate, parallel to the substrate, and on the glass substrate Reacting the mixture to form a silica coating on the substrate;
Including chemical vapor deposition process. The chemical vapor deposition process of claim 1, wherein the gaseous precursor mixture comprises 10% or more water vapor. The chemical vapor deposition process of claim 1, wherein the gaseous precursor mixture comprises 40% or more water vapor. The chemical vapor deposition process according to any one of claims 1 to 3, wherein the silica coating is formed at a deposition rate of about 150 nm * m / min or more. The chemical vapor deposition process according to any one of claims 1 to 4, wherein the surface of the substrate is substantially under atmospheric pressure when the silica coating is formed. 6. The chemical vapor deposition process of any of claims 1-5, further comprising depositing a tin oxide coating on the surface of the glass substrate, wherein the silica coating is deposited on the tin oxide coating. . The gaseous precursor mixture is formed prior to introduction into a coating apparatus.
The chemical vapor deposition process of any one of -6. When the silica coating is deposited, the glass substrate is about 1100 ° F. (60
The chemical vapor deposition process according to any one of claims 1 to 7, which is 0 ° C to 1400 ° F (750 ° C). The glass substrate is moving when the silica coating is deposited.
9. The chemical vapor deposition process according to claim 1. The chemical vapor deposition process according to any one of claims 1 to 9, wherein the gaseous precursor mixture comprises 50% to 98% water vapor. 11. A chemical vapor deposition process according to any one of the preceding claims, wherein the gaseous precursor mixture comprises oxygen and silane compounds in a ratio exceeding 4: 1. The glass substrate has a thickness of 125 in / min (3.175 m / min) to 600 in / mi.
The chemical vapor deposition process according to claim 1, wherein the chemical vapor deposition process is moving at a speed of n (15.24 m / min). A chemical vapor deposition process for depositing a silica coating,
Providing a function of moving a glass substrate having a surface on which the silica coating is deposited;
Depositing a tin oxide coating on the surface of the glass substrate;
Mixing a gaseous silane compound, oxygen, a radical scavenger and water vapor to form a gaseous precursor mixture;
The gaseous precursor mixture is allowed to flow in the direction of the tin oxide coat surface of the glass substrate in parallel with the coat surface, and the mixture is reacted at or near the coat substrate surface, and on the coated glass substrate surface. Forming a silica coating on the substrate, and cooling the coated glass substrate to room temperature;
Including chemical vapor deposition process. The chemical vapor deposition process of claim 13, wherein the surface of the glass substrate is substantially under atmospheric pressure when the tin oxide and silica coating are deposited. The chemical vapor deposition process according to claim 13 or 14, wherein the tin oxide coating is deposited directly on the surface of the glass substrate with a thickness of 5 nm to 100 nm. 16. The chemical vapor deposition process of any one of claims 13-15, wherein the tin oxide coating is deposited using a halogen-containing tin precursor compound. When the silica coating is deposited, the glass substrate is about 1100 ° F. (60
The chemical vapor deposition process according to any one of claims 13 to 16, which is from 0 ° C to 1400 ° F (750 ° C). The chemical vapor deposition process according to claim 13, wherein the glass substrate is moving at a speed of 125 in / min to 600 in / min. The chemical vapor deposition process of any one of claims 13-18, wherein the tin oxide and silica coating forms two separate coating layers on the glass substrate. 20. A chemical vapor deposition process according to any one of claims 13 to 19, wherein the gaseous precursor mixture comprises more than 10% water vapor.